It is important, in particular in mass production such as in the construction of motor-vehicles, to tighten nuts on the screws or screws in tapped holes with the right tightening force. Motor-driven screwing machines are often used in this type of production, and the torque developed by such machines is dependent on how they are adjusted; this torque may vary quite suddenly during use, often causing high variations of the force applied for tightening the screw or the nut, and consequently, the parts to be assembled. If the operator does not check the tightening force at the right moment, for example with a torque wrench, there is a risk that certain assemblies may be unsufficiently tightened.